<template>
  <div class="demo-block" :class="[blockClass, { hover: hovering }]" @mouseenter="hovering = true" @mouseleave="hovering = false">
    <div class="source">
      <slot name="source"></slot>
    </div>
    <div ref="meta" class="meta">
      <div v-if="$slots.default" class="description">
        <slot></slot>
      </div>
      <div class="highlight">
        <slot name="highlight"></slot>
      </div>
    </div>
    <div ref="control" class="demo-block-control" :class="{ 'is-fixed': fixedControl }" @click="isExpanded = !isExpanded">
      <transition name="arrow-slide">
        <i :class="[iconClass, { hovering: hovering }]"></i>
      </transition>
      <transition name="text-slide">
        <span v-show="hovering">{{ controlText }}</span>
      </transition>
      <div class="control-button-container control-button-container-left">
        <el-button v-show="isExpanded && hasSetup" size="small" type="text" class="control-button" @click.stop="onSwitchSyntax">
          {{ showSetup ? langConfig['switch-button-option-text'] : langConfig['switch-button-setup-text'] }}
        </el-button>
      </div>
      <div class="control-button-container">
        <el-button v-show="isExpanded" ref="copyButton" size="small" type="text" class="control-button copy-button" @click.stop="copy">
          {{ langConfig['copy-button-text'] }}
        </el-button>
        <el-tooltip effect="dark" :content="langConfig['tooltip-text']" placement="right">
          <transition name="text-slide">
            <el-button v-show="isExpanded" size="small" type="text" class="control-button run-online-button" @click.stop="goCodepen">
              {{ langConfig['run-online-button-text'] }}
            </el-button>
          </transition>
        </el-tooltip>
      </div>
    </div>
  </div>
</template>
<script>
import { nextTick } from 'vue'
import hljs from 'highlight.js'
import clipboardCopy from 'clipboard-copy'
import compoLang from '../i18n/component.json'
import { stripScript, stripStyle, stripTemplate, stripSetup, removeSetup } from '../util'
const version = '1.0.0' // element version
const stripTemplateAndRemoveTemplate = code => {
  const result = removeSetup(stripTemplate(code))
  if (result.indexOf('<template>') === 0) {
    const html = result.replace(/^<template>/, '').replace(/<\/template>$/, '')
    return html
      .replace(/^[\r?\n|\r]/, '')
      .replace(/[\r?\n|\r]$/, '')
      .trim()
  }
  return result
}
const sanitizeHTML = str => {
  const temp = document.createElement('div')
  temp.textContent = str
  return temp.innerHTML
}
export default {
  data() {
    return {
      codepen: {
        script: '',
        html: '',
        style: ''
      },
      hovering: false,
      isExpanded: false,
      fixedControl: false,
      scrollParent: null,
      showSetup: false,
      hasSetup: false
    }
  },
  computed: {
    lang() {
      return this.$route.path.split('/')[1]
    },

    langConfig() {
      return compoLang.filter(config => config.lang === this.lang)[0]['demo-block']
    },

    blockClass() {
      return `demo-${this.lang} demo-${this.$router.currentRoute.value.path.split('/').pop()}`
    },

    iconClass() {
      return this.isExpanded ? 'el-icon-caret-top' : 'el-icon-caret-bottom'
    },

    controlText() {
      return this.isExpanded ? this.langConfig['hide-text'] : this.langConfig['show-text']
    },

    codeArea() {
      return this.$el.getElementsByClassName('meta')[0]
    },

    codeAreaHeight() {
      if (this.$el.getElementsByClassName('description').length > 0) {
        return this.$el.getElementsByClassName('description')[0].clientHeight + this.$el.getElementsByClassName('highlight')[0].clientHeight + 20
      }
      return this.$el.getElementsByClassName('highlight')[0].clientHeight
    },

    displayDemoCode() {
      return this.showSetup ? this.codepen.setup : this.codepen.script
    }
  },

  watch: {
    isExpanded(val) {
      // this.codeArea.style.height = val ? `${this.codeAreaHeight + 1}px` : '0'
      this.setCodeAreaHeight()
      if (!val) {
        this.fixedControl = false
        this.$refs.control.style.left = '0'
        this.removeScrollHandler()
        return
      }
      setTimeout(() => {
        this.scrollParent = document.querySelector('.page-component__scroll > .el-scrollbar__wrap')
        this.scrollParent && this.scrollParent.addEventListener('scroll', this.scrollHandler)
        this.scrollHandler()
      }, 200)
    }
  },

  created() {
    const highlight = this.$slots.highlight()
    if (highlight && highlight[0]) {
      let code = ''
      let cur = highlight[0]
      if (cur.type === 'pre' && cur.children && cur.children[0]) {
        cur = cur.children[0]
        if (cur.type === 'code') {
          code = cur.children
        }
      }
      if (code) {
        this.codepen.html = stripTemplateAndRemoveTemplate(code)
        this.codepen.script = stripScript(code)
        this.codepen.style = stripStyle(code)
        this.codepen.setup = stripSetup(code)
        if (this.codepen.setup) {
          this.hasSetup = true
        }
      }
    }
  },
  beforeUnmount() {
    this.removeScrollHandler()
  },

  mounted() {
    this.prettyCode()
  },

  methods: {
    getCodeAreaHeight() {
      if (this.$el.getElementsByClassName('description').length > 0) {
        return this.$el.getElementsByClassName('description')[0].clientHeight + this.$el.getElementsByClassName('highlight')[0].clientHeight + 20
      }
      return this.$el.getElementsByClassName('highlight')[0].clientHeight
    },
    setCodeAreaHeight() {
      this.codeArea.style.height = this.isExpanded ? `${this.getCodeAreaHeight() + 1}px` : '0'
    },
    prettyCode() {
      nextTick(() => {
        const highlight = this.$el.querySelector('.highlight')
        const hlcode = highlight.querySelector('pre code')
        const innerScript = `<script>
  ${this.displayDemoCode}
${'</sc' + 'ript>'}
`
        const innerStyle =
          this.codepen.style && this.codepen.style.trim()
            ? `<style>
  ${this.codepen.style}
</style>
`
            : ''
        hlcode.innerHTML = sanitizeHTML(`<template>
  ${this.codepen.html}
</template>

${this.displayDemoCode ? innerScript : ''}${innerStyle}`)

        nextTick(() => {
          if (this.$el.getElementsByClassName('description').length === 0) {
            highlight.style.width = '100%'
            highlight.borderRight = 'none'
          }
          try {
            hljs.highlightElement(hlcode)
          } catch (error) {
            console.log(error)
          }
        })
      })
    },
    onSwitchSyntax() {
      this.showSetup = !this.showSetup
      this.prettyCode()
      this.$nextTick(this.setCodeAreaHeight)
    },
    copy() {
      const res = clipboardCopy(`
<template>
${this.codepen.html}
</template>

<script>
${'  ' + this.displayDemoCode}
\<\/script>

<style>
${this.codepen.style}
</style>
`)

      res
        .then(() => {
          this.$message({
            showClose: true,
            message: this.langConfig['copy-success'],
            type: 'success'
          })
        })
        .catch(() => {
          this.$message({
            showClose: true,
            message: this.langConfig['copy-error'],
            type: 'error'
          })
        })
    },
    goCodepen() {
      // since 2.6.2 use code rather than jsfiddle https://blog.codepen.io/documentation/api/prefill/
      const { script, html, style } = this.codepen
      let resourcesTpl =
        '<scr' +
        'ipt src="//cdn.jsdelivr.net/npm/vue@next"></scr' +
        'ipt>' +
        '\n<scr' +
        `ipt src="//cdn.jsdelivr.net/npm/element-plus"></scr` +
        'ipt>' +
        '\n<scr' +
        `ipt src="//cdn.jsdelivr.net/npm/vue-cesium@next"></scr` +
        'ipt>'
      if (this.blockClass.includes('demo-vc-overlay-echarts')) {
        resourcesTpl += '\n<scr' + `ipt src="//cdn.jsdelivr.net/npm/echarts"></scr` + 'ipt>'
      }
      let htmlTpl = `${resourcesTpl}\n<div id="app">\n${html.trim()}\n</div>`
      let cssTpl = `@import url("//cdn.jsdelivr.net/npm/element-plus/dist/index.css");\n${(
        style || ''
      ).trim()}\n@import url("//cdn.jsdelivr.net/npm/vue-cesium@next/dist/index.css");\n${(style || '').trim()}\n`
      cssTpl += `
        .demo-viewer .el-row:last-child {
            margin-bottom: 0;
        }

        .demo-viewer .el-row {
            border-radius: 100px;
            align-items: baseline;
        }

        .demo-viewer .demo-toolbar {
            position: absolute;
            left: 1%;
            top: 1%;
            min-width: 185px;
            z-index: 100;
            color: #fff;
            background-color: rgba(0,0,0,.2);
        }

        .demo-vc-viewer .el-switch:first-child {
            margin-left: 20px;
        }

        .demo-vc-viewer .el-switch {
            margin: 20px 20px 20px 0;
        }

        .demo-vc-datasource-custom {
          .el-switch__label.is-active {
            color: #409eff;
          }
        }

        .block {
          padding: 30px 24px;
          overflow: hidden;
          border-bottom: solid 1px #eff2f6;
          &:last-child {
            border-bottom: none;
          }
        }

        .el-row {
            border-radius: 100px;
            align-items: baseline;

            &:last-child {
              margin-bottom: 0;
            }
          }
          .el-button {
            margin: 10px 10px 10px 0;

            &:first-child {
              margin-left: 20px;
            }
          }

          .el-switch {
            margin: 20px 20px 20px 0;

            &:first-child {
              margin-left: 20px;
            }
          }

          .el-switch__label {
            color: white;
          }
        `
      let jsTpl = script
        ? script
            .replace(/export default/, 'var Main =')
            .trim()
            .replace(/import ({.*}) from 'vue'/g, (s, s1) => `const ${s1} = Vue`)
            .replace(/import ({.*}) from 'element-plus'/g, (s, s1) => `const ${s1} = ElementPlus`)
            .replace(/import ({.*}) from 'vue-cesium'/g, (s, s1) => `const ${s1} = VueCesium`)
        : 'var Main = {}'
      jsTpl += '\n;const app = Vue.createApp(Main);\napp.use(ElementPlus);\napp.use(VueCesium);\napp.mount("#app")'
      const data = {
        js: jsTpl,
        css: cssTpl,
        html: htmlTpl
      }
      const form = document.getElementById('fiddle-form') || document.createElement('form')
      while (form.firstChild) {
        form.removeChild(form.firstChild)
      }
      form.method = 'POST'
      form.action = 'https://codepen.io/pen/define/'
      form.target = '_blank'
      form.style.display = 'none'

      const input = document.createElement('input')
      input.setAttribute('name', 'data')
      input.setAttribute('type', 'hidden')
      input.setAttribute('value', JSON.stringify(data))

      form.appendChild(input)
      document.body.appendChild(form)

      form.submit()
      document.body.removeChild(form)
    },

    scrollHandler() {
      const { top, bottom, left } = this.$refs.meta.getBoundingClientRect()
      const controlBarHeight = 44
      this.fixedControl = bottom + controlBarHeight > document.documentElement.clientHeight && top <= document.documentElement.clientHeight
      this.$refs.control.style.left = this.fixedControl ? `${left}px` : '0'
    },

    removeScrollHandler() {
      this.scrollParent && this.scrollParent.removeEventListener('scroll', this.scrollHandler)
    }
  }
}
</script>
<style lang="scss" scoped>
.demo-block {
  border: solid 1px #ebebeb;
  border-radius: 3px;
  transition: 0.2s;

  &.hover {
    box-shadow: 0 0 8px 0 rgba(232, 237, 250, 0.6), 0 2px 4px 0 rgba(232, 237, 250, 0.5);
  }

  code {
    font-family: Menlo, Monaco, Consolas, Courier, monospace;
  }

  .demo-button {
    float: right;
  }

  .source {
    padding: 24px;
  }

  .meta {
    background-color: #fafafa;
    border-top: solid 1px #eaeefb;
    overflow: hidden;
    height: 0;
    transition: height 0.2s;
  }

  .description {
    padding: 20px;
    box-sizing: border-box;
    border: solid 1px #ebebeb;
    border-radius: 3px;
    font-size: 14px;
    line-height: 22px;
    color: #666;
    word-break: break-word;
    margin: 10px;
    background-color: #fff;

    p {
      margin: 0;
      line-height: 26px;
    }

    code {
      color: #5e6d82;
      background-color: #e6effb;
      margin: 0 4px;
      display: inline-block;
      padding: 1px 5px;
      font-size: 12px;
      border-radius: 3px;
      height: 18px;
      line-height: 18px;
    }
  }

  .highlight {
    pre {
      margin: 0;
    }

    code.hljs {
      margin: 0;
      border: none;
      max-height: none;
      border-radius: 0;

      &::before {
        content: none;
      }
    }
  }

  .demo-block-control {
    border-top: solid 1px #eaeefb;
    height: 44px;
    box-sizing: border-box;
    background-color: #fff;
    border-bottom-left-radius: 4px;
    border-bottom-right-radius: 4px;
    text-align: center;
    margin-top: -1px;
    color: #d3dce6;
    cursor: pointer;
    position: relative;

    &.is-fixed {
      position: sticky;
      bottom: 0;
    }

    i {
      font-size: 16px;
      line-height: 44px;
      transition: 0.3s;
      &.hovering {
        transform: translateX(-40px);
      }
    }

    > span {
      position: absolute;
      transform: translateX(-30px);
      font-size: 14px;
      line-height: 44px;
      transition: 0.3s;
      display: inline-block;
    }

    &:hover {
      color: #409eff;
      background-color: #f9fafc;
    }

    & .text-slide-enter,
    & .text-slide-leave-active {
      opacity: 0;
      transform: translateX(10px);
    }

    .control-button-container {
      line-height: 40px;
      position: absolute;
      top: 0;
      right: 0;
      padding-left: 5px;
      padding-right: 25px;
    }
    .control-button-container-left {
      left: 0;
      width: 100px;
      padding-left: 14px; // 14 + 10 = 24px .hljs code padding left 24
    }

    .control-button {
      font-size: 14px;
      margin: 0 10px;
    }
  }
}
</style>
